@sfoster1982,
As
@esgee48 mentioned, it's your frame - you can do whatever you like. He's also correct regarding the (now) unknown tension remaining in the main strings.
However, I don't really agree with the second part of his statement. Once you have removed all of the cross strings (and, of course, the cross knots), you shouldn't have any trouble finding tie-off locations for the "replacement" crosses.
At that point, you should have 4 tie-off locations available once again (regardless of whether you previously tied off onto mains or crosses).
Those locations should be... the same 2 locations where your cross knots were
previously located, as well as the exact same locations on the
opposite side of the frame (unless your racquet has an asymmetrical design [meaning the crosses need to be installed in a specific direction]).
Example: If your top cross had been at 5H and your bottom cross had been at 6T, you should then have 5HL, 5HR, 6TL & 6TR available.
Therefore, there's really no need to enlarge any grommets.
Just to be clear... I do NOT advocate replacing only crosses. However,
IF you are determined to do this, make sure you understand the forces involved & properly mount the frame before proceeding.
Cutting out all of the crosses, without first having the frame mounted, stands a good chance of damaging your frame.
I made the following video specifically for people who ask this very question (since this topic tends to come up from time to time).
Cheers, Wes